First Online: 11 October 2016Received: 01 July 2016Accepted: 08 September 2016

Abstract

BackgroundCerebral hypoxia-ischemia H-I is an important stress factor involved in the disruption of the blood–brain barrier BBB following stroke injury, yet the cellular and molecular mechanisms on how the human BBB responds to such injury remains unclear. In this study, we investigated the cellular response of the human BBB to chemical and environmental H-I in vitro.

MethodsIn this study, we used immortalized hCMEC-D3 and IMR90 stem-cell derived human brain microvascular endothelial cell lines IMR90-derived BMECs. Hypoxic stress was achieved by exposure to cobalt chloride CoCl2 or by exposure to 1 % hypoxia and oxygen-glucose deprivation OGD was used to model ischemic injury. We assessed barrier function using both transendothelial electrical resistance TEER and sodium fluorescein permeability. Changes in cell junction integrity were assessed by immunocytochemistry and cell viability was assessed by trypan-blue exclusion and by MTS assays. Statistical analysis was performed using one-way analysis of variance ANOVA.

ResultsCoCl2 selectively disrupted the barrier function in IMR90-derived BMECs but not in hCMEC-D3 monolayers and cytotoxic effects did not drive such disruption. In addition, hypoxia-OGD stress significantly disrupted the barrier function by selectively disrupting tight junctions TJs complexes. In addition, we noted an uncoupling between cell metabolic activity and barrier integrity.

ConclusionsIn this study, we demonstrated the ability of IMR90-derived BMECs to respond to hypoxic-ischemic injury triggered by both chemical and environmental stress by showing a disruption of the barrier function. Such disruption was selectively targeting TJ complexes and was not driven by cellular apoptosis. In conclusion, this study suggests the suitability of stem cell-derived human BMECs monolayers as a model of cerebral hypoxia-ischemia in vitro.

AbbreviationsBBBblood-brain barrier

BMECsbrain microvascular endothelial cells

DMEMDulbecco’s modified eagle medium

GDglucose deprivation

H-Ihypoxia-ischemia

ODoxygen deprivation

OGDoxygen-glucose deprivation

PBSphosphate-buffered saline solution

TEERtransendothelial electrical resistance

TJtight junctions

Electronic supplementary materialThe online version of this article doi:10.1186-s12987-016-0042-1 contains supplementary material, which is available to authorized users.